1. Field of the Invention
The present invention relates to the control of the communication between a receiving means and a module communicating with the same, and in particular to such methods and devices suitable for being used in conditional access and access control systems, wherein single chip modules are used in terminal devices.
2. Description of Prior Art
The term “single chip module” generally includes chip modules as they are for example used with EC-cards, telephone cards, in cards for access control, in cards for conditional access systems or in cards for authentication. The term single chip module further includes such chip modules which are either integrated in devices in the form of components or which extend those devices.
The use of EC (eurocheque) cards as a means of payment has become a firm part of today's payments. With these cards so-called smart cards (intelligent cards) are used in order to save or process information, like for example crypto keys or cryptograms. But also in many other areas smart cards are used increasingly, like for example with telephone cards, credit cards and other electronic identifications. A single chip module or one chip module, respectively, is a central component of these smart cards, wherein its functionality may reach from the one of a memory medium to the one of a crypto chip. Apart from the replaceable single chip modules which are arranged on card carriers there exist further ones which are directly integrated in devices in order to store data, like for example a crypto key, safe from an unauthorized access.
The systems in which single chip modules are used may generally be classified into two groups. Conditional access systems are systems with a restricted access, like they are for example used when receiving chargeable pay-TV or other media services. The terminal and receive devices, respectively, which are used with these conditional access systems include for example pay-TV decoders and decoding devices, respectively, or mobile receive devices, like for example mobile telephones. Access control systems, however, include systems or applications for access control, like they are for example used in the form of credit cards for assuring a safe cashless money transfer or in the form of money cards and telephone cards as a replacement for cash. The terminal devices used with these systems include for example credit card or bank terminals. Safety modules, like for example single chip modules are used everywhere today, where confidential information is to be stored so that it cannot be read out, is transportable and protected against third party access.
Chip cards, like they are for example used with conditional access systems, are used for the terminal device-sided storage of receive authorizations for services, like for example receiving certain chargeable TV programs and of cryptographic keys. Such chip cards are in most cases not firmly connected to a terminal device, like for example a pay-TV decoder, but are removable and exchangeable from the same. Examples for such exchangeable chip cards for a storage of cryptographic keys and receive authorizations on the terminal device-side are pay-TV smart cards or credit cards. To this end, reference is made to the article “Conditional Access or Wie kann man den Zugriff auf Rundfunksendungen kontrollieren?” by Jörg Schwenk in Bernd Seiler (ed.): Taschenbuch der Telekompraxis 1996, Schiele & Schön, Berlin 1996.
In operation, the single chip module is communicatively connected to the respective terminal device into which the single chip module is inserted, for example via a card reader or a fixed wire, if the single chip module is integrated into the terminal device. The communication of the single chip module with the terminal device is defined via a communication protocol, which is determined in the ISO standard 7618. The ISO standard guarantees that the communication between the terminal device, like for example the pay-TV decoder, and the single chip module is uniformly determined on the protocol level, especially with applications in which exchangeable single chip modules such as those which are integrated in smart cards are used.
Depending on the application or use, respectively, an additional software may be installed in the single chip modules, which requires an application-dependent communication software adjusted to this additional software on the side of the terminal device. In case for example that due to increased safety requirements, due to a compromised system with restricted access or for performance increase of a single chip module a new single chip module with a new software is to be used, it may be required to change the application specific communication protocol. This causes that the software needs to be updated with all associated terminal devices. These necessary adaptations lead to incompetitively high costs, if they are implementable at all, mainly with mobile terminal devices, like for example devices firmly built into vehicles.
One disadvantage with today's systems based on single chip modules is therefore that the communication software in the respective terminal devices is only designed for a data communication protocol format which is specific for the single chip module at the time of generating the communication software. If a different communication protocol for a communication between the single chip module and the terminal device or another single chip module is to be used with a different data communication protocol at a later point of time, because for example safety problems occurred due to pirate attacks in a safety system, then, apart from the single chip module, also the software on the terminal device side needs to be changed or the terminal device needs to be exchanged. In the case of cashless money transfer the bank terminals would for example have to be adapted when introducing new bank or credit cards, which would require considerable efforts.